(a) Technical Field of the Invention
The present invention relates to LEDs, and in particular, to an LED illumination device which is mounted by a light-reflective hood so that a larger light projection area is obtained.
(b) Description of the Prior Art
Conventional light bulbs for vehicles normally use tungsten bulbs, and recently, in order to extend longevity and to save current, LEDs are used to extend their longevity for long hours of operation. In view of methods of light emission between the LED and tungsten bulbs, LED provides direct light projection and the tungsten bulbs provide a fan-shape illumination. The LED bulbs employed in vehicles have a direct light projection and insufficient brightness, and so a number of LED bulbs have to be used to achieve the desired effect. This drawback is also found in home appliances where a light-reflective hood is mounted onto the LED. In view of this, the hood installation is problematic if LED is employed. Thus, the application of LED is not popular in home.
The light of an LED is characterized in that if the angle of illumination is smaller, the illumination will be brighter, and therefore, the LED will not provide a fan-shaped light source. The angle of illumination of LED can be improved by modifying the structure of the LED bulb. U.S. patent application Ser. No. 434,510 discloses an improved structure by mounting a plurality of LEDs on the circuit board and the lower edge of the circuit board is stepped so that the light source from the LED is reflected by a lamp hood. However, the light source after reflected from the lamp hood is weaker and the brightness is insufficient, and the fan-like light projection of the tungsten bulb cannot be achieved. Accordingly, it is an object of the present invention to provide an LED illumination device which mitigates the above drawbacks.